The aim of the study is to investigate the antigen-unspecific effect of a 3 months supplementation with a food for special medical purposes (FSMP) in form of a lozenge containing beta-lactoglobulin (BLG), iron, retinoic acid, zinc and polyphenols (holo-BLG) in patients with allergic rhinoconjunctivitis caused by cat (hair/dander) and the associated symptoms (symptom type and severity) during exposure to cat allergen in an Allergen Exposure Chamber (AEC).

Inclusion Criteria:

• At least 1 year of clinically relevant cat allergy
• positive SPT (wheal >3mm)
• Positive NPT
• Increase in TSS >3 during the 1st exposure in the AEC
• Verbal and written consent

Exclusion Criteria:

• subjects <18 years
• subjects taking immunosuppressive drugs such as systemic corticosteroids, cyclosporine, etc.
• subjects who have received or are currently receiving sublingual or subcutaneous immunotherapy (SLIT/SCIT) for cat allergy in the last 2 years prior to V0
• clinically relevant overreactions to the ingredients of holoBLG, in particular subjects with a milk protein allergy or pronounced lactose intolerance
• subjects with severe asthma and/or a history of uncontrolled asthmatic attacks in the last three months before the selection process (GINA 4 and 5).
• subjects with an FEV1 <70% (predicted value) prior to exposure in the AEC
• Lack of verbal and written informed consent
• subjects who are not proficient in the German language
• History of serious chronic medical illness and/or any condition for which the local investigator believes that participation in the study could pose a risk to the individual
• Pregnancy and lactation
• Contraindications and/or history of adrenaline intolerance and/or emergency medications
• Concurrent use of anti-allergic medications and/or inadequate washout period of these anti-allergic medications prior to the selection process and exposure in the exposure chamber
• TSS ≥ 6 at t0 of first exposure in the AEC
• Subjects who have a history of ingestion of holoBLG